Pigmentation differences, exploiting

If a technique is to exploit differences in pigmentation, it needs prior measurements of the light-absorbing characteristics of the algae. Hence, the action spectrum for fluorescence of chlorophyll a is a tool for identifying the color types of algae (i). 

Mica-Tek has an interesting approach to exploiting the variety of forms and colors of mica. A range of mica-based products have been developed which differ in the color and the shape of particle as well as in their glittering and sparkling effects. These decorative pigments are used in housewares, bathwares, toys, interior decorating, etc. 

Other techniques are used to identify pigments based on their molecular fragments. These techniques include UV-visible reflectance spectroscopy, infrared (IR) spectroscopy, mass spectrometry, and X-ray diffraction (XRD). Some thermal methods exploit differences in physical characteristics that are sensitive to the bulk properties of a paint sample. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) are often used. Finally, separation techniques such as liquid chromatography (LC) have been used to identify a wide range of dyes. 

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